The present invention relates to a method, an apparatus, and a computer program for calculating a risk assessment value of an event sequence, with which a risk assessment value indicating a risk of the occurrence of a predetermined incident is calculated for each sequence of some of events that occur in a time series.
It is often considered that a large number of events occur in a time series as omens of a critical incident before the occurrence of the critical incident. Hence, it is preferable to estimate the possibility that a critical incident will occur based on a group of events (hereinafter referred to as “an event sequence”) that occur in a time series, and to issue a warning in advance.
However, it is often unclear which event sequence is linked to the occurrence of what critical incident. In addition, it is difficult to list all the possible cases in advance, and the number of event sequences considered to occur is often huge. Under these circumstances, there have been developed many systems for predicting what incident will possibly occur by using a method such as modeling with a neuron model or the like, or estimating a risk assessment value.
Japanese Patent Application Publication No. 2009-237914, for example, discloses a risk prediction device with which risk prediction for a case including both a majority class and a minority class can be made according to actual instances on the basis of their scores calculated in consideration of their attributes. In JP2009-237914, an attribute highly related to a risk factor can be accurately identified even from imbalanced training data in which the number of instances in the majority class is much larger than that of the minority class.